Electric switch for alarm clocks



28, 19360 H. FRHTZfiCH y fi ELECTRIC SWITCH FOR ALARE? CLOCKS Fild Feb. 3, 1932 Patented Jan. 28, 1936 UNITED STATES PATENT OFFICE Application February 3, 1932, Serial No. 590,617 In Germany February 11, .1931

6 Claims.

My invention relates to improvements in timecontrolled electric switches which are operated at a predetermined time to open or close an electric circuit.

Objects of the invention are:

To provide simple means which permit swift fitting and removing of a suitable electric switch to and from any alarm clock with a time-controlled alarm winding shaft and without having to make any change in the alarm-clock as boring, cutting, soldering, brazing, or any such like process requiring tools;

To provide simple means, so as to permit exchanging the alarm-clock easily for another alarm-clock, the casing of which can be of any different shape and size, which alarm-clock is further fitted with a different thread on its winding shaft;

To provide simple means in such manner that they permit reversing the switch easily from automatic switching-on to automatic switching-off and inversely;

To provide simple means in such manner that they permit using the alarm-clock easily in the ordinary way without use of the switch.

For the attainment of the aforesaid objects and ends, my invention consists in the novel details of construction and in the combination, connection and arrangement of parts, hereinafter more fully described and claimed, the descriptive matter being supplemented by the accompanying drawing, which constitutes a part of this application and in which:

Figure 1 is a perspective view of an alarmclock with the invention applied;

Fig. 2 is a longitudinal section as seen on the plane of the line 2--2 of the Figs. 3, 4 and looking in the direction indicated by the arrows;

Fig. 3 is a rear elevation of the invention and an elevation of the device for the connection of the switch to the electric circuit which shall be influenced by the switch;

Fig. 4 is a front elevation of the invention;

Fig. 5 is a sectional view as seen on the plane of the line 55 of Fig. 2 looking in the direction indicated by the arrows.

Figs. 6 and '7 represent a second, and Figs. 8 to a third form of construction of the invention. The kind of view of the invention in these figures can easily be ascertained by comparison with the Figures 1 to 5.

In the drawing, I represents the casing of the switch, which is here the stationary portion of the switch and composed of insulation material, 2 the cover of the casing of the switch, 3 screws for fastening the cover 2 to the casing I, 4 the switch shaft which is the rotary portion of the switch by turning of which relatively to the stationary portion the switch is operated, 5 the coupling for the inflexible connection of the switch and the alarm- 5 clock, 6 a cap with pointer I for adjustment of the switch, 8 contacts for the circuit to be connected up, 9 contacts for the connection of the source of current, I0 contacts for the consumer of current (apparatus, engine, heating, relay or 10 such like), I I contacts for the connection of the switch. A second automatic switch can be connected up to contacts I2, so that in the first place the one of the switches can cut out automatically and that then the second switch can switch on automatically, without any need of a new adjustment between both the operations.

By means of the screw-nuts I3, the contacts .8 are held fast in the casing of the switch and connected with the strips of sheet-metal I4 and I5. Metal strip I4, on its free end, is formed as fixed switch contact member. The movable contact member is represented by the sheetmetal strip I6, which is carried round the body of insulation I1 and fastened with screw I8. Body H, on its circumference, has the two tongues I9 and 20, which serve to limit the rotation of the switch shaft in the on and offpositions respectively. The middle part 21 of the switch shaft which is passed through body I1 is of square cross-section to prevent a turning of both parts towards each other. Mentioned limits of the rotation of the switch shaft in the on or oil position are obtained by stopping of the tongue I9 or 20 at the switchcasing I.

To insure a rapid switching, the springy metal strip I4 is provided with bend 22 and with an insulating body 24 which is secured to the metal strip I4 at the bend 22 with the rivet 23. The turning of the switch-casing as prevented by means presently explained. The turning of the switch-shaft causes a tension in the contacts I4 and I6 (by means of the bend 22), so that the contact I6 snaps on or snaps ofi.

To further ensure the off position, the metal strip I5 also has a bend 25 over which the contact I6 glides. Metal strip I5 touches metal strip I6 in every position of the switch-shaft, see Fig. 5, so that metal strip I6 is always electrically connected with one of the contacts 8.

To prevent the turning of the stationary portion of the switch with the rotary portion under the action of the alarm winding shaft, said stationary portion is connected with the clock casing. Because the connection of the alarm winding shaft with the rotary portion of the switch is inflexible, the stationary portion of the switch can be supported through the rotary portion by the alarm winding shaft and for that reason there is no need that the connecting element between the stationary portion of the switch and the clock casing supports the stationary portion. This is of great importance because the alarm clocks are not constructed for the attachment of an element in such a manner that it can support the switch and therefore in such a case the construction or at least the manipulation of the switching device would be very complicated. It is important for example, that the switch can be removed from the rear side of the clock and attached again in a, simple and rapid manner since the clock mechanism has generally to be wound up daily and when doing so the said removing of the switch is preferable or even necessary in order to obtain convenient access to the setting knobs of the clock.

With regard to these reflections and the other objects of this invention above-mentioned the 7 connection between the stationary portion and the clock casing in the new switching device is effected by a catch member attached to said stationary portion and constructed so as to prevent or limit the rotation of the stationary portion with the rotary portion under the action of the alarm winding shaft only by bearing against the clock casing under the action of the alarm winding shaft and to permit on all alarm clocks a movement of the switch in the direction of the alarm winding shaft and vertically thereto for uncoupling the switch from the alarm winding shaft and removing the switch from the rear side of the clock without alteration of its (of the catch member) adjustment and--setting aside the said uncouplingwithout alteration of the clock.

In Figs. 1-3 of the drawing this catch member comprises a hook 26 which is fastened to cord Zl. The cord 27 is attached to the switch-casing by being passed through plug 28 and secured by set-screw 29. The pin 36, square and conical, serves to hold the plug 28 in place in the recess of the switch-casing 1, yet permits the removal iof the plug, which simplifies the operating of the switch, which will be shown presently. The ends 31 and 32 of the switch-shaft are of square section and have equal dimensions, so that the shaftend 3! or theshaft-end 32 fits into the square channel 33 of the coupling 5. There is the same square channel 34 in the switch-cap 6 which also has a pin 35 that can fit into the channel 33.

At the places marked 4, the switch-shaft is mounted in the switch-casing permitting re- .order to wind up, the winding-shaft must be turned to the right. Further suppose that the switch is expected to switch off automatically,

in this case the switch must be mounted as shown in Fig. 2.,

The hook 26 can for instance be attached to a leg of the clock or according to Fig. 1 fastened to the handle of the clock and cord 27' drawn through plug 28, which is mounted on switchcasing I, so far that switch-casing l, in regard to the clock, is turning only within close limits. Then the switch-shaft and alarm-winding-shaft has to be turned to the right as far as possible by means. of the switch-cap 6, so that the pointer 1 points to on, which is the case when cap 5 is fastened correctly to shaft '5. This can be managed by marking shaft i accordingly.

The moment the set time on the alarm mechanism has arrived, the alarm-winding-shaft and the switch-shaft will rotate to the left until the off position is reached. Further revolving of the shaft is prevented by means of the catch l8 and cord 21.

In order to obtain the automatic switching on, the end 32 of the switch-shaft has to be engaged with the coupling and the cap 6 to be attached to the end Si of the switch-shaft. By turning the cap 6 to the right the switch reaches the off position and the automatic runningdown of the alarm-winding-shaft brings the switch to the on position. 7

From the foregoing description can easily be seen the necessary arrangement for automatic switching on or off when the alarm-windingshaft is turning automatically to the right and not to the left.

The changing from switching automatically on to switching automatically off may necessitate the disconnecting of the cord 21 between the clock and the switch. In order to free the cord-connection remove hook 26 from the alarmclock or simply withdraw plug 28 from switchcasing l. The squared ends of the coupling and of the switch shaft permit an easy disconnection of these two parts.

When the removing of the switch shall effect only convenient access to the setting knobs of the clock, it is not necessary to free the cordconnection, since by the movability of the hook as well as by the flexibility of the cord the switch can be uncoupled and removed from the rear side of the clock without alteration of the adjustment and attachment of the cord-connection, whereat it is assumed that the cord, when it is adjusted, is not pulled on quite tightly. The flexibility of the cord also makes the adaptation of the switch-device to thershape and size of the clock particularly easy.

When it is desired to'use the clock without the switch it is unnecessary to unscrew the coupling. The coupling can. serve as alarmwinding cap, or else use the cap 5 by inserting the pin 35 into the coupling.

Figs. 6 and 7 differ from they foregoing arrangement only in respect to the catch, the latter resting on the clock-casing. In this case (Figs. 6 and 7) the catch member consists of the arm 31 secured to plug 28 by the set-screw 29 in .such a manner, that by the running down of the alarm-winding-shaft the movement of the arm 31 is arrested, for example by stopping on a leg of the clock and thus preventing the turning of the switch-casing l. The free end of .the arm 3'! extends parallel or substantially parallel to the alarm-winding-shaft and has such a length that it can reach the casing of all the usual alarm clocks without special adjustment thereto, whereby it can fit all shapes and sizes of the clocks only by adjustment of said free end to different distances from the alarm-winding shaft 75 by aid of the set-screw 29. Furthermore the free end of the arm 31 is preferably forked (see Fig. 6) thus embracing for instance a leg of the clock and herewith simplifying the operating of the switch.

By changing from switching automatically on to switching automatically off and vice versa, it is useful not to disturb the position of the arm 3! in the plug 28, but disengage plug 28 and replace the same when the switch-casing has its new position.

Figs. 8-10 show a third catch-device. Arm 38 is secured to the switch-casing I by the pin 39 which is of square section. Arm 38 ends in a fork 40 extending parallel to the alarm winding shaft as the fork of the arm 31. To permit an adaptation of the part 40 to the form of the clock, a joint 4| is provided.

In order to adapt the switch to big and small clocks, i. e. to be able to change the distance of the fork to the switch-shaft, the arm 38 can be bent as shown in Fig. 10, which process will be facilitated by the bend 42 provided.

All shown catch members are constructed to bear against the projections which are usually situated on the periphery of the clock casing, such as for instance, the legs of the alarm clock or the handle at the top of the clock casing. Such a connection with the alarm clock casing is easier to control than in the case of a connection with the setting knobs on the back wall of the clock. In the latter case, owing to the close proximity of the setting knobs to the alarm winding shaft, a considerable abutment pressure is set up which it is desirable to avoid in order to spare the clockwork mechanism as much as possible.

In regard to specified matter I wish it to be understood that I do not desire to be limited to the exact details of construction shown and described, for obvious modifications will occur to a person skilled in the art.

I claim:

1. Switching means for controlling an electric circuit by the alarm winding shaft of a normal alarm clock, comprising a complete electric switch, said electric switch having a casing and a shaft mounted rotatably in said casing for effecting the switching, the latter shaft being adapted to be coupled to the alarm winding shaft so as to turn therewith and, when so coupled, to be supported upon the alarm winding shaft and to carry the entire switch, and a catch member attached to the said casing and constructed so as to prevent or limit the rotation of the casing with the mentioned shaft under the action of the alarm winding shaft only by bearing loosely against the clock casing under action of the alarm winding shaft.

2. Switching means for controlling an electric circuit by the alarm winding shaft of a normal alarm clock, comprising a complete electric switch, said electric switch having a casing and a shaft mounted rotatably in said casing for effecting the switching, the latter shaft being adapted to be coupled to the alarm winding shaft so as to turn therewith and, when so coupled, to be supported upon the alarm winding shaft and to carry'the entire switch, and a catch member consisting of a cord attached to the said casing and a hook fastened to the free end of said cord and adapted to be fastened on the alarm clock casing.

3. Switching means for controlling an electric circuit by the alarm winding shaft of a normal alarm clock, comprising a complete electric switch, said electric switch having a casing and a shaft mounted rotatably in said casing for effecting the switching, the latter shaft being adapted to be coupled to the alarm winding shaft so as to turn therewith and, when so coupled, to be supported upon the alarm winding shaft and to carry the entire switch, and an arm attached to the said casing and having a free end extending in the direction of the alarm winding shaft and adapted to bear against a projecting portion of the clock casing under the action of the alarm winding shaft.

4. Switching means for controlling an electric circuit by the alarm winding shaft of a normal alarm clock, comprising a complete electric switch, said electric switch having a casing and a shaft mounted rotatably in said casing for effecting the switching, a coupling member having a screw thread at one end for connection to the alarm winding shaft and having the other end squared for application of the mentioned switch shaft and carrying the entire switch, and a catch member attached to the said casing and constructed so as to prevent or limit the rotation of the casing with the mentioned switch shaft under the action of the alarm winding shaft only by bearing loosely against the clock casing under the action of the alarm winding shaft.

5. Switching means for controlling an electric circuit by the alarm winding shaft of a normal alarm clock, comprising a complete electric switch, said electric switch having a casing and a shaft mounted rotatably in said casing for effecting the switching, both ends of the latter shaft being of square cross section and having the same dimensions, a coupling member having a screw thread at one end for connection to the alarm winding shaft and having the other end squared so that it can fit each of the ends of the said switch shaft to carry the entire switch, and a catch member, attached to the said casing and constructed so as to prevent or limit the rotation of the casing with the mentioned switch shaft under the action of the alarm winding shaft only by bearing loosely against the clock casing under the action of the alarm winding shaft.

6. Switching means for controlling an electric circuit by the alarm winding shaft of a normal alarm clock, comprising a complete electric switch, said electric switch having a casing and a shaft mounted rotatably in said casing for effe-cting the switching, this shaft being adapted to be coupled to the alarm winding shaft so as to turn therewith and, when so coupled, to be supported upon the alarm winding shaft and to carry the entire switch, and a catch member attached to the said casing and constructed so as to prevent or limit the rotation of the casing with the mentioned switch shaft, under the action of the alarm winding shaft, only by bearing against the projections on the periphery of the clock casing under the action of the alarm winding shaft.

HERMANN FRITZSCH. 

